:root {
  --clr-blue: #0A1E3C;
  --clr-yellow: #FFC300;
  --clr-red: #E5383B;
  --clr-stone: #6C757D;
  --clr-moss: #8A9A5B;
  --clr-terra: #C97C5D;
  --clr-cream: #F5F1E8;
  --clr-ink: #1B1B1B;
  --clr-sky: #BBDEFB;
  --clr-amber: #F4A261;
  --font-display: "Poppins", "Arial Black", "Microsoft YaHei", sans-serif;
  --font-body: "Open Sans", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "Roboto Mono", "SFMono-Regular", Consolas, monospace;
  --font-index: "Open Sans", sans-serif;
  --container: 1200px;
  --header-h: 78px;
  --radius: 6px;
  --shadow-1: 0 20px 60px rgba(10, 30, 60, 0.16);
  --shadow-2: 0 12px 32px rgba(10, 30, 60, 0.22);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--clr-ink);
  background-color: var(--clr-cream);
  min-height: 100vh;
}

body::before,
body::after {
  content: "";
  position: fixed;
  top: 0;
  bottom: 0;
  width: clamp(12px, 2vw, 28px);
  background: var(--clr-blue);
  z-index: 1200;
  pointer-events: none;
}

body::before {
  left: 0;
}

body::after {
  right: 0;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  margin-top: 0;
  color: var(--clr-ink);
}

h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.8rem, 4vw, 2.75rem);
}

h3 {
  font-size: clamp(1.15rem, 2vw, 1.45rem);
}

p {
  margin-top: 0;
}

a {
  color: var(--clr-blue);
  text-underline-offset: 2px;
}

ul,
ol {
  padding-left: 1.2em;
}

:focus-visible {
  outline: 3px solid var(--clr-yellow);
  outline-offset: 3px;
}

button {
  font-family: inherit;
  line-height: 1.4;
}

img {
  max-width: 100%;
  height: auto;
}

.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 4vw, 2.5rem);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: clamp(12px, 2vw, 28px);
  top: -100px;
  z-index: 2000;
  padding: 0.8rem 1.2rem;
  background: var(--clr-yellow);
  color: var(--clr-blue);
  text-decoration: none;
  border-radius: 0 0 8px 8px;
  font-weight: 700;
  transition: top 0.25s ease;
}

.skip-link:focus {
  top: 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--clr-blue);
  color: var(--clr-cream);
  border-bottom: 4px solid var(--clr-yellow);
}

.site-header__inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
  min-height: var(--header-h);
}

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -4px;
  height: 4px;
  width: 0%;
  background: var(--clr-red);
  z-index: 1100;
  pointer-events: none;
  transition: width 0.1s linear;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--clr-cream);
  flex-shrink: 0;
}

.brand__badge {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  background: var(--clr-yellow);
  color: var(--clr-blue);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: -0.04em;
  border-radius: 4px 12px 4px 12px;
  box-shadow: 4px 4px 0 var(--clr-red);
  transform: rotate(-3deg);
  transition: transform 0.25s ease;
}

.brand:hover .brand__badge {
  transform: rotate(0deg) scale(1.04);
}

.brand__label {
  display: flex;
  flex-direction: column;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  line-height: 1.1;
  color: var(--clr-cream);
}

.brand__label small {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--clr-stone);
}

.site-nav {
  margin-inline: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.2rem, 1.2vw, 1.1rem);
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 0.45rem 0.35rem;
  color: var(--clr-cream);
  text-decoration: none;
  font-size: 0.92rem;
  letter-spacing: 0.04em;
  border-bottom: 3px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: var(--clr-yellow);
  border-bottom-color: var(--clr-yellow);
}

.site-nav__link[aria-current="page"] {
  color: var(--clr-yellow);
  border-bottom-color: var(--clr-red);
}

.site-nav__cta {
  display: none;
}

.site-header__actions {
  flex-shrink: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.4rem;
  border-radius: 999px;
  border: 2px solid transparent;
  font-family: var(--font-body);
  font-size: 0.92rem;
  font-weight: 700;
  text-decoration: none;
  line-height: 1.2;
  cursor: pointer;
  transition: transform 0.2s ease, background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.btn--accent {
  background: var(--clr-yellow);
  color: var(--clr-blue);
  box-shadow: 0 4px 0 var(--clr-blue), 0 8px 24px rgba(255, 195, 0, 0.35);
}

.btn--accent:hover,
.btn--accent:focus-visible {
  background: var(--clr-amber);
  transform: translateY(-3px);
}

.btn--ghost {
  background: transparent;
  color: var(--clr-cream);
  border-color: rgba(245, 241, 232, 0.6);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  color: var(--clr-yellow);
  border-color: var(--clr-yellow);
}

.site-nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 9px;
  background: transparent;
  border: 1px solid rgba(245, 241, 232, 0.3);
  border-radius: 8px;
  cursor: pointer;
  flex-shrink: 0;
}

.site-nav-toggle__line {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--clr-yellow);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__line:nth-child(2) {
  opacity: 0;
}

.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

body.nav-open {
  overflow: hidden;
}

.site-footer {
  position: relative;
  background: var(--clr-blue);
  color: var(--clr-cream);
  border-top: 4px solid var(--clr-yellow);
  border-bottom: 4px solid var(--clr-yellow);
  padding-block: 3.5rem 2rem;
  margin-top: clamp(3rem, 8vw, 6rem);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -4px;
  right: 0;
  width: 30%;
  height: 4px;
  background: var(--clr-red);
}

.site-footer__inner {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  margin-bottom: 2.5rem;
}

.site-footer__logo {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--clr-cream);
  margin-bottom: 0.6rem;
}

.site-footer__logo::before {
  content: "YB";
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  background: var(--clr-yellow);
  color: var(--clr-blue);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  border-radius: 4px 10px 4px 10px;
  box-shadow: 3px 3px 0 var(--clr-red);
  transform: rotate(-4deg);
}

.site-footer__logo small {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--clr-stone);
}

.site-footer__slogan {
  margin: 0;
  color: var(--clr-yellow);
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.site-footer__title {
  color: var(--clr-yellow);
  margin: 0 0 1rem;
}

.site-footer__contact ul,
.site-footer__links ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.site-footer__contact li,
.site-footer__links li {
  margin-bottom: 0.55rem;
  color: rgba(245, 241, 232, 0.85);
  font-size: 0.95rem;
}

.site-footer__links a {
  color: var(--clr-cream);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-bottom-color 0.2s ease;
}

.site-footer__links a:hover,
.site-footer__links a:focus-visible {
  color: var(--clr-yellow);
  border-bottom-color: var(--clr-yellow);
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid rgba(245, 241, 232, 0.18);
  padding-top: 1.5rem;
  font-size: 0.85rem;
  color: rgba(245, 241, 232, 0.62);
}

.site-footer__bottom p {
  margin: 0;
}

.site-footer__top {
  position: fixed;
  right: calc(clamp(12px, 2vw, 28px) + 1.2rem);
  bottom: 1.5rem;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--clr-yellow);
  color: var(--clr-blue);
  border: none;
  font-size: 1.4rem;
  box-shadow: 0 6px 18px rgba(229, 56, 59, 0.45);
  cursor: pointer;
  z-index: 1201;
  transition: transform 0.2s ease;
}

.site-footer__top:hover,
.site-footer__top:focus-visible {
  transform: translateY(-4px);
}

.section {
  padding: clamp(3.5rem, 9vw, 7rem) 0;
  position: relative;
}

.section--tight {
  padding-block: clamp(2.5rem, 5vw, 4rem);
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-bottom: clamp(2rem, 5vw, 3.5rem);
}

.index-label {
  font-family: var(--font-index);
  font-weight: 300;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--clr-stone);
  margin: 0 0 0.45rem;
}

.grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 3rem);
}

.grid--split {
  grid-template-columns: 1.15fr 1fr;
  align-items: center;
}

.grid--thirds {
  grid-template-columns: repeat(3, 1fr);
}

.layout-double {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 30%);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
}

.layout-double__aside {
  position: sticky;
  top: calc(var(--header-h) + 1.5rem);
  padding: 1.5rem;
  background: var(--clr-blue);
  color: var(--clr-cream);
  border-radius: 12px 24px 12px 24px;
  border-left: 4px solid var(--clr-yellow);
  box-shadow: var(--shadow-2);
}

.layout-double__aside p:last-child {
  margin-bottom: 0;
}

.prose {
  max-width: 70ch;
}

.prose > * + * {
  margin-top: 1.2rem;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  font-family: var(--font-index);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 1.5rem 0 0;
  margin: 0;
  list-style: none;
}

.breadcrumb li + li::before {
  content: " / ";
  color: var(--clr-stone);
  margin-right: 0.4rem;
}

.breadcrumb a {
  color: var(--clr-blue);
  text-decoration: none;
}

.breadcrumb [aria-current="page"] {
  color: var(--clr-stone);
}

.card {
  background: #ffffff;
  border: 1px solid rgba(10, 30, 60, 0.08);
  border-radius: 12px 24px 12px 24px;
  padding: clamp(1.5rem, 3vw, 2.25rem);
  box-shadow: var(--shadow-1);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-2);
}

.card__title {
  font-size: 1.25rem;
  margin-bottom: 0.6rem;
}

.card__meta {
  font-family: var(--font-mono);
  color: var(--clr-stone);
  font-size: 0.8rem;
}

.picture {
  position: relative;
  overflow: hidden;
  background: var(--clr-sky);
  border-radius: 12px 24px 12px 24px;
  aspect-ratio: 16 / 10;
}

.picture img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.picture::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 2px solid var(--clr-yellow);
  border-radius: inherit;
  opacity: 0.5;
  transition: opacity 0.25s ease;
  pointer-events: none;
}

.picture:hover::after {
  opacity: 1;
}

.img-slot {
  display: grid;
  place-items: center;
  min-height: 240px;
  border-radius: 12px 24px 12px 24px;
  background:
    linear-gradient(135deg, rgba(187, 222, 251, 0.4) 25%, transparent 25%),
    linear-gradient(225deg, rgba(255, 195, 0, 0.3) 25%, transparent 25%),
    var(--clr-blue);
  color: var(--clr-cream);
  font-family: var(--font-index);
  font-weight: 300;
  font-size: 0.85rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.img-slot::before {
  content: attr(data-label);
  text-align: center;
  padding: 1rem;
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem 0.9rem;
  padding: 0.8rem 0 1.5rem;
}

.filter-btn {
  appearance: none;
  border: 1px solid var(--clr-blue);
  background: transparent;
  color: var(--clr-blue);
  font-family: var(--font-body);
  padding: 0.5rem 1.1rem;
  border-radius: 999px;
  font-size: 0.9rem;
  line-height: 1.3;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.filter-btn:hover,
.filter-btn:focus-visible {
  border-color: var(--clr-amber);
  box-shadow: inset 0 0 0 1px var(--clr-amber);
}

.filter-btn.is-active,
.filter-btn[aria-pressed="true"] {
  background: var(--clr-blue);
  color: var(--clr-yellow);
  border-color: var(--clr-blue);
  box-shadow: 0 4px 0 var(--clr-red);
}

.filter-item[hidden] {
  display: none !important;
}

.stat {
  font-family: var(--font-mono);
  color: var(--clr-blue);
  font-weight: 700;
}

.stat--large {
  font-size: clamp(2.2rem, 5vw, 4rem);
  line-height: 1;
}

.stat--yellow {
  color: var(--clr-yellow);
}

.score {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--clr-ink);
  background: var(--clr-yellow);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  display: inline-block;
}

.data-bar {
  height: 10px;
  background: rgba(10, 30, 60, 0.1);
  border-radius: 999px;
  overflow: hidden;
}

.data-bar__fill {
  height: 100%;
  width: 60%;
  background: linear-gradient(90deg, var(--clr-yellow), var(--clr-amber));
  border-radius: inherit;
}

.data-bar__fill--blue {
  background: var(--clr-blue);
}

.data-bar__fill--red {
  background: var(--clr-red);
}

.data-bar__fill--moss {
  background: var(--clr-moss);
}

.path-map {
  position: relative;
  display: grid;
  gap: 1.25rem;
  margin-top: 2rem;
}

.path-map::before {
  content: "";
  position: absolute;
  left: 22px;
  top: 24px;
  bottom: 24px;
  width: 2px;
  background: repeating-linear-gradient(to bottom, var(--clr-yellow) 0 6px, transparent 6px 12px);
}

.path-step {
  position: relative;
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 1rem;
  align-items: start;
  padding: 1.25rem;
  background: #ffffff;
  border-radius: 12px 24px 12px 24px;
  box-shadow: 0 6px 20px rgba(10, 30, 60, 0.08);
}

.path-step__index {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  background: var(--clr-blue);
  color: var(--clr-yellow);
  font-family: var(--font-mono);
  font-weight: 700;
  border-radius: 50%;
  border: 3px solid var(--clr-yellow);
  z-index: 1;
  box-shadow: 0 0 0 3px var(--clr-cream);
}

.path-step__title {
  margin: 0 0 0.25rem;
  font-size: 1.1rem;
}

.path-step__text {
  margin: 0;
  color: var(--clr-stone);
  font-size: 0.95rem;
}

.acc {
  border-top: 1px solid rgba(10, 30, 60, 0.1);
}

.acc__item {
  border-bottom: 1px solid rgba(10, 30, 60, 0.1);
}

.acc__title {
  width: 100%;
  background: transparent;
  border: none;
  padding: 1.2rem 0;
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 700;
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--clr-ink);
}

.acc__title::after {
  content: "+";
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--clr-red);
  transition: transform 0.3s ease;
  flex-shrink: 0;
  margin-left: 1rem;
}

.acc__item[data-open] .acc__title::after {
  content: "–";
  transform: rotate(135deg);
}

.acc__content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.acc__item[data-open] .acc__content {
  max-height: 600px;
  padding-bottom: 1.2rem;
}

.decor-line {
  display: block;
  width: 64px;
  height: 4px;
  background: var(--clr-yellow);
  border-radius: 999px;
  margin: 1rem 0 2rem;
}

.decor-line::after {
  content: "";
  display: block;
  width: 20px;
  height: 4px;
  background: var(--clr-red);
  margin-top: 4px;
  border-radius: inherit;
}

.js-ready [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.65s cubic-bezier(0.22, 0.61, 0.36, 1), transform 0.65s cubic-bezier(0.22, 0.61, 0.36, 1);
  will-change: opacity, transform;
}

.js-ready [data-reveal].is-in-view {
  opacity: 1;
  transform: none;
}

@media (max-width: 920px) {
  .site-header__inner {
    gap: 0.8rem;
  }

  .site-header__actions {
    display: none;
  }

  .site-nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    right: 0;
    background: var(--clr-blue);
    padding: 1rem 5% 1.5rem;
    display: none;
    border-bottom: 4px solid var(--clr-yellow);
    box-shadow: var(--shadow-2);
  }

  .site-nav[data-open] {
    display: block;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.3rem;
  }

  .site-nav__link {
    display: block;
    padding: 0.8rem 0.5rem;
    width: 100%;
    font-size: 1.05rem;
  }

  .site-nav__cta {
    display: inline-flex;
    margin-top: 1rem;
  }

  .grid--thirds,
  .layout-double {
    grid-template-columns: 1fr;
  }

  .layout-double__aside {
    position: static;
  }

  .site-footer__inner {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 767px) {
  body::before,
  body::after {
    display: none;
  }

  .site-footer__top {
    right: 1rem;
  }
}

@media (max-width: 620px) {
  .brand__badge {
    width: 40px;
    height: 40px;
    font-size: 0.85rem;
  }

  .brand__label {
    font-size: 1rem;
  }

  .site-footer__inner {
    grid-template-columns: 1fr;
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .js-ready [data-reveal] {
    opacity: 1;
    transform: none;
  }
}